Dipping Titan implants in Irrisept solution (0.05% chlorhexidine gluconate) and exposure to various aerobic, anaerobic, and fungal species

Abstract

Abstract Background The organisms causing penile implant infections are changing from predominantly indolent gram-positive infections to more aggressive gram-negative and fungal infections because of antibiotic selection pressures based on novel next-generation sequencing DNA data. Aim To evaluate the effectiveness of Irrisept solution (0.05% chlorhexidine gluconate) in decreasing isolate colony counts from a Titan implant by using a novel kill time washout methodology to mirror real-world usage. Methods Sterilized Titan discs were dipped in Irrisept or saline. An inoculum of 109 organisms of a single bacterial or fungal species was placed on the discs. Bacterial and fungal strains were tested: Bacteroides fragilis, Candida albicans, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. The discs were then irrigated 3 times with Irrisept or saline. Microorganisms were sonicated off the discs and placed on appropriate agar and conditions for each species. The plates were incubated for 48 to 72 hours at the temperature and under the conditions appropriate for each species. Colonies on the plates were hand counted. Outcomes Irrisept effectively decreased microbial colony counts in all the species tested. Results Irrisept was shown to effectively decrease microbial colony counts from 3 to 6 log10 in all species tested. A 3-log10 reduction is considered the target level of performance that would indicate that a compound or product has effective killing activity against an organism of interest. The saline control with bulb syringe irrigation did not demonstrate reduction of microbial colony counts in any of the species tested. Clinical Implications Irrisept is effective against all of the organisms causing modern-day infections with penile implant surgery and may decrease clinical infection rates to lower levels. Strengths and Limitations The strength of this study is that we used quantitative microbial reduction counting and the largest array of bacterial and fungal species causing modern-day penile implant infections. The limitation is that this is an in vitro study and the clinical implications of our findings are not yet known. Conclusion Quantitative microbial reduction counting shows that Irrisept is effective against the most commonly known modern-day organisms causing penile implant infections.